The embodiments of the present invention generally relate to lighting systems that are digitally controlled and to the lighting fixtures used therein, in particular multiparameter lighting fixtures having one or more image projection lighting parameters.
Lighting systems are typically formed by interconnecting, via a communications system, a plurality of lighting fixtures and providing for operator control of the plurality of lighting fixtures from a central controller. Such lighting systems may contain multiparameter light fixtures, which illustratively are light fixtures having two or more individually remotely adjustable parameters such as focus, color, image, position, or other light characteristics. Multiparameter light fixtures are widely used in the lighting industry because they facilitate significant reductions in overall lighting system size and permit dynamic changes to the final lighting effect. Applications and events in which multiparameter light fixtures are used to great advantage include showrooms, television lighting, stage lighting, architectural lighting, live concerts, and theme parks. Illustrative multi-parameter light devices are described in the product brochure entitled “The High End Systems Product Line 2001” and are available from High End Systems, Inc. of Austin, Tex.
Prior to the advent of relatively small commercial digital computers, remote control of light fixtures from a central controller was done with either a high voltage or low voltage current; see, e.g., U.S. Pat. No. 3,706,914, issued Dec. 19, 1972 to Van Buren, and U.S. Pat. No. 3,898,643, issued Aug. 5, 1975 to Ettlinger, both of which are incorporated by reference herein for all purposes. With the widespread use of computers, digital serial communication was widely adopted as a way to achieve remote control; see, e.g., U.S. Pat. No. 4,095,139, issued Jun. 13, 1978 to Symonds et al., and U.S. Pat. No. 4,697,227, issued Sep. 29, 1987 to Callahan, both of which are incorporated by reference herein for all purposes.
In 1986, the United States Institute of Theatre Technology (“USITT”) developed a digital communications system protocol for multiparameter light fixtures known as DMX512. Basically, the DMX512 protocol is comprised of a stream of data which is communicated one-way from the control device to the light fixture using an Electronics Industry Association (“EIA”) standard for multipoint communications know as RS-485.
A variety of different types of multiparameter light fixtures are available. One type of advanced multiparameter light fixture, which is referred to herein as an image projection lighting device (“IPLD”), uses a light valve to project images onto a stage or other projection surface. A light valve, which is also known as an image gate, is a device, such as a digital micro-mirror (“DMD”) or a liquid crystal display (“LCD”), that forms the image that is to be projected. Various IPLD's and IPLD systems are described in U.S. patent application Ser. No. 10/190,926, filed Mar. 4, 2002, U.S. patent application Ser. No. 10/206,162, filed Jul. 26, 2002, and U.S. patent application Ser. No. 10/290,660, filed Nov. 8, 2002, all of which are incorporated by reference herein for all purposes.
In their common application, IPLD's are used to project their images upon a stage or other projection surface. Control of the IPLD's is affected by an operator using a central controller that may be located several hundred feet away from the projection surface. In many applications, the stage, or projection surface, is also elevated such that, with the central controller located at a significant distance from the stage, the operator can not see the image projected upon the stage. This lack of vision may prevent effective control of the projected images from the central controller. For example, the operator may not be able to set the desired focus parameter value of the image, or set the projected image to the desired position, upon a remote projection surface because the operator may not be able to see the projection surface from the central controller location.
In a given application, there may be up to hundreds of IPLD's used to illuminate the projection surface, with each IPLD having many parameters that may be adjusted to create a scene. Once a scene is constructed, the operator of the central controller can adjust the parameters of the many IPLD's in order to construct a new scene. The work of adjusting or programming the parameters to the desired values for the many IPLD's to create a scene can take quite some time. Many times the scenes are created by the operator during a rehearsal and the time for programming the many IPLD's has limitations.
Since the operator of the control system often can not see the projected images from the central controller location, the desired focus, position or other parameters of the IPLD's may be set with the operator having a human spotter in proximity to the stage or projection surface. The spotter can communicate verbally, such as over a radio, to give directions to the operator as to when the desired image or effect is achieved. In certain applications, a portable remote control unit of the central controller can be used by the operator in close proximity to the stage or projection surface for setting the focus, position or other parameter of the image projected upon projection surface. Although this eliminates the spotter, the operator can not see the projected images from the central controller, making last minute adjustments difficult.
Thus, there remains a need in the art for methods and apparatus for improving the control system of a remotely located IPLD. The embodiments of the present invention are directed to methods and apparatus for improved lighting devices and complimentary control systems that seek to overcome the limitations of the prior art.